河北省地下流体水位对远场大震的响应特征研究

Co-seismic Response Characteristics Research of Subsurface Fluid Water Level for the Far-field Earthquake in Hebei Province

选取汶川Ms8.0、日本Ms9.0、印尼Ms8.6、巴基斯坦Ms7.8四个远大地震,从"一震多井"和"一井多震"的角度分析河北省地下流体不同井孔水位的响应特征,探讨水位变化的机理。结果表明:水位同震响应形态以水震波为主,部分为水震波伴随阶变或只有阶变;同一口井的水位同震阶变方向是固定不变的,水位阶跃上升集中区可能就是未来地震危险区;含水层岩性为灰岩或花岗岩,导水系数大、渗透性能好的井孔水位同震响应幅度大;震中距相近时,不同井孔水位的同震响应时间有很大差异,含水层岩体结构的不同是主导因素;峰4井水位的映震能力近几年在逐渐增强。

The authors select our great earthquakes： Wenchuan MsS. 0, Japan Ms8.6, Indonesia Ms8.6, and Pakistan Ms7.8. From ＂an earthquake many wells＂ and ＂a well many earthquakes＂ perspectives, we analyze co- seismic response characteristics of different borehole water level of Hebei subsurface fluid and investigate the mechanism of water level changes. The results show： the co-seismic response forms of water level are mainly water waves, and part of the water waves is accompanied by step changes or only step changes; the co-seismic step change direction of the same well water level is fixed, and the clusters of water level step rise may be the seismic hazard zone in the future; if the aquifer lithology is limestone or granite, hydraulic conductivity coefficient is larger, and permeability better, the margin of borehole water level is larger; water levels co-seismic response times of different borehole are very different when the epicentral distance is similar, different aquifer rock structures are the dominant factor; reflecting capacity of Feng -4 well water level is gradually increasing in recent years.